Assessing high-energy x-ray and proton irradiation effects on electrical properties of P-GaN and N-GaN thin films

The effects of ionizing and displacement irradiation of high-energy x-ray and 2-MeV proton on GaN thin films were investigated and compared in this study. The electrical properties of both P-GaN and N-GaN, separated from power devices, were gauged for fundamental analysis. It was found that the electrical properties of P-GaN were improved as a consequence of the disruption of the Mg–H bond induced by high-dose x-ray irradiation, as indicated by the Hall and circular transmission line model. Specifically, under a 100-Mrad(Si) x-ray dose, the specific contact resistance ρ_c of P-GaN decreased by 30%, and the hole carrier concentration increased significantly. Additionally, the atom displacement damage effect of a 2-MeV proton of 1 × 10¹³ p/cm² led to a significant degradation of the electrical properties of P-GaN, while those of N-GaN remained unchanged. P-GaN was found to be more sensitive to irradiation than N-GaN thin film. The effectiveness of x-ray irradiation in enhancing the electrical properties of P-GaN thin films was demonstrated in this study.